Motion control for actuation of surgical table height

Abstract

A surgical table with motion control and improved transitions between primary and secondary actuation systems is described. A surgical table may include: a first actuation system having at least one primary actuator powered with a primary variable speed electric motor; a second actuation system having at least two secondary actuators powered respectively with secondary variable speed electric motors; and a controller adapted to regulate positions of the primary and secondary actuators. This controller is operable to raise the tabletop by implementing logic to: control the primary variable speed electric motor based on a primary actuator deceleration profile that decreases a speed of extending the primary actuator while raising the tabletop with the secondary actuators; and control the secondary variable speed electric motors based on a secondary actuator acceleration profile that increases a speed of extending the secondary actuators while raising the tabletop with the primary actuator.

What is claimed is: 
     
         1 . A surgical table, comprising:
 a tabletop;   a first actuation system coupled to the tabletop, the first actuation system including at least one primary actuator that is powered with a primary variable speed electric motor;   a second actuation system coupled to the tabletop, the second actuation system including at least two secondary actuators that are powered respectively with secondary variable speed electric motors; and   a controller adapted to regulate positions of the primary and secondary actuators, wherein the controller is operable to raise the tabletop with logic to:
 control the primary variable speed electric motor based on a primary actuator deceleration profile that decreases a speed of extending the primary actuator while raising the tabletop with the secondary actuators; and 
 control the secondary variable speed electric motors based on a secondary actuator acceleration profile that increases a speed of extending the secondary actuators while raising the tabletop with the primary actuator. 
   
     
     
         2 . The surgical table of  claim 1 , wherein the primary actuator is a linear actuator capable of raising the tabletop to a maximum primary height, and wherein the primary actuator deceleration profile is used until the maximum primary height is reached. 
     
     
         3 . The surgical table of  claim 2 , wherein a speed provided by the secondary actuator acceleration profile progressively increases to reach a maximum speed of the secondary actuators before the primary actuator reaches the maximum primary height. 
     
     
         4 . The surgical table of  claim 2 , wherein a speed provided by the primary actuator deceleration profile progressively decreases, and wherein a speed provided by the secondary actuator acceleration profile progressively increases before the maximum primary height of the tabletop is reached, to transition from a maximum speed of the primary actuator to a maximum speed of the secondary actuators. 
     
     
         5 . The surgical table of  claim 1 , wherein the controller is operable to lower the tabletop with logic to:
 control the secondary variable speed electric motors based on a secondary actuator deceleration profile that decreases a speed of retracting the secondary actuators while lowering the tabletop with the primary actuator; and   control the primary variable speed electric motor based on a primary actuator acceleration profile that increases a speed of retracting the primary actuator while lowering the tabletop with the secondary actuators.   
     
     
         6 . The surgical table of  claim 1 , wherein the primary actuator deceleration profile includes a stopping distance for primary height actuation provided by the primary actuator, the stopping distance calculated based on a known steady speed of the primary height actuation, and
 wherein the secondary actuator acceleration profile includes a starting distance for secondary height actuation provided by the secondary actuators, the starting distance calculated based on a known steady speed of the secondary height actuation.   
     
     
         7 . The surgical table of  claim 6 , wherein a timing to begin use of the primary actuator deceleration profile and the secondary actuator acceleration profile is based on the stopping distance for the primary height actuation provided by the primary actuator. 
     
     
         8 . The surgical table of  claim 1 , wherein the speed of extending the primary actuator and the speed of extending the secondary actuators are further based on a current height of the tabletop and respective characteristics of the primary actuator and the secondary actuators. 
     
     
         9 . The surgical table of  claim 1 , wherein the secondary actuators are a pair of linear actuators capable of raising the tabletop to a maximum secondary height, and wherein the secondary actuators are further capable of causing rotation of the tabletop relative to a center axis. 
     
     
         10 . The surgical table of  claim 9 , wherein the controller is operable to change an angle of the tabletop using logic configured to:
 rotate the tabletop about the center axis to a user-controlled angle, based on extension and retraction of respective actuators of the pair of linear actuators.   
     
     
         11 . The surgical table of  claim 10 , wherein the user-controlled angle is between −45 degrees and 45 degrees. 
     
     
         12 . The surgical table of  claim 1 , wherein a speed used by the primary variable speed electric motor to extend the primary actuator and a speed of the secondary variable speed electric motors to extend the secondary actuators is based on the positions of the at least one primary actuator and the at least two secondary actuators. 
     
     
         13 . The surgical table of  claim 12 , wherein the controller is further adapted to determine the positions of the at least one primary actuator and the at least two secondary actuators based on a measurement of strokes of a shaft of a respective actuator. 
     
     
         14 . The surgical table of  claim 13 , wherein the measurement of strokes is measured with a shaft encoder sensor of the respective actuator. 
     
     
         15 . The surgical table of  claim 1 , further comprising:
 a user interface control communicatively coupled to the controller, the user interface control to receive a user command to raise the tabletop or a user command to lower the tabletop.   
     
     
         16 . A method for controlling positions of a surgical table, comprising:
 identifying a first position of a first actuation system of the surgical table, the first actuation system including at least one primary actuator that is powered with a primary variable speed electric motor, wherein the primary actuator is coupled to a tabletop of the surgical table;   identifying a second position of a second actuation system of the surgical table, the second actuation system including at least two secondary actuators that are powered respectively with secondary variable speed electric motors, wherein the secondary actuators are coupled to the tabletop of the surgical table;   receiving a command to raise the tabletop;   controlling the primary variable speed electric motor to change the first position of the first actuation system, based on a primary actuator deceleration profile that decreases a speed of extending the primary actuator while raising the tabletop with the secondary actuators; and   controlling the secondary variable speed electric motors to change the second position of the second actuation system, based on a secondary actuator acceleration profile that increases a speed of extending the secondary actuators while raising the tabletop with the primary actuator.   
     
     
         17 . The method of  claim 16 , wherein the primary actuator is a linear actuator capable of raising the tabletop to a maximum primary height, and wherein the primary actuator deceleration profile is used until the maximum primary height is reached. 
     
     
         18 . The method of  claim 17 , wherein a speed provided by the primary actuator deceleration profile progressively decreases, and wherein a speed provided by the secondary actuator acceleration profile progressively increases before the maximum primary height of the tabletop is reached, to transition from a maximum speed of the primary actuator to a maximum speed of the secondary actuators. 
     
     
         19 . The method of  claim 16 , further comprising:
 controlling the secondary variable speed electric motors based on a secondary actuator deceleration profile that decreases a speed of retracting the secondary actuators while lowering the tabletop with the primary actuator; and   controlling the primary variable speed electric motor based on a primary actuator acceleration profile that increases a speed of retracting the primary actuator while lowering the tabletop with the secondary actuators.   
     
     
         20 . A non-transitory machine-readable storage medium comprising instructions, which when executed by circuitry of a controller for a surgical table, causes the circuitry to perform operations that:
 determine a first position of a first actuation system of the surgical table, the first actuation system including at least one primary actuator that is powered with a primary variable speed electric motor, wherein the primary actuator is coupled to a tabletop of the surgical table;   determine a second position of a second actuation system of the surgical table, the second actuation system including at least two secondary actuators that are powered respectively with secondary variable speed electric motors, wherein the secondary actuators are coupled to the tabletop of the surgical table; and   change the first position and the second position of the primary and secondary actuators respectively, in response to a command to raise the tabletop, with operations to:
 control the primary variable speed electric motor based on a primary actuator deceleration profile that decreases a speed of extending the primary actuator while raising the tabletop with the secondary actuators; and 
 control the secondary variable speed electric motors based on a secondary actuator acceleration profile that increases a speed of extending the secondary actuators while raising the tabletop with the primary actuator.